


Fill In

by DoctorFatCat



Category: GOT7
Genre: 2jaeyoung, 2youngjae - Freeform, Alpha/Beta/Omega Dynamics, Beta!Youngjae, M/M, OT3, Omegaverse, Plot What Plot/Porn Without Plot, Smut, alpha!Jaebum, dom!jinyoung, i totally made that name up okay, omega!jinyoung, someone told me the right name, thank you c:
Language: English
Status: Completed
Published: 2017-10-16
Updated: 2017-10-16
Packaged: 2018-12-25 15:22:34
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,546
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12038703
Author URL: https://archiveofourown.org/users/DoctorFatCat/pseuds/DoctorFatCat
Summary: They’d never planned for this to happen.





	Fill In

**Author's Note:**

> I wrote this in the span of an hour because I was bored. But it was made in a hurry and I didn't proof read.  
> It's 5 am and I gotta sleep so I hope you enjoy it??  
> They have their Arrival's hairstyles in this okay.  
> Update from 4 hours later: Wow damn this is a hot mess lmao. I shouldn't be allowed to write fics when half asleep.  
> I'm gonna fix this in some days when I have the time, sorry  
> Update: I changed the publication date because I edited it. After over a month, yeah.<3

They’d never planned for this to happen.

The both of them, Jaebum and Jinyoung, had been together since high school. An omega and an alpha. They’d mated on Jinyoung’s twenty-first birthday and nothing had changed from then. Not the way they loved each other, only maybe because they loved the other more every day.

As mates, their heat and rut had gotten in sync, their bodies preparing for conceiving babies. So it meant that, of course, they’d want to be together when it struck, leaving the both of them to run it out together, Jinyoung still on contraceptives since they weren’t ready for kids yet. Even though fantasizing about their pups was common, taking care of children wasn’t an easy task and they knew that.

Sadly, sometimes the world wouldn’t be helpful, and they’d have to find ways to get off and find release on their own when separated.

It was when Jinyoung’s work had to send him to Hong Kong for a month that he finally decided to do something about it.

“We’re getting a fill-in.” He tells Jaebum, who looks at him with an incredulous expression.

“What? Why? Are you not satisfied by me anymore? Have I done something wrong?” He starts blaming himself as always, something the younger says it’s his worst trait.

“No, baby. You’re enough. Of course you are. But we’re not going to be together on our mating days and I don’t want you to have to spend them alone again.” He explains.

“But what about you?”

“I’ll take suppressants. I wouldn’t be able to get off while on a business trip anyways.”

Jaebum understands. He would take suppressants himself if he could, but his body seems to react negatively to them, as if he's got an allergy. So the alpha always spends their separate days whining for his mate and trying to find release on his own. Needless to say, it’s never enough.

“Are you sure?” The older asks, head on the other’s lap, the both of them on their couch in the living room, the tv on but no one was paying attention to it anymore. “We don’t have to.”

Jinyoung chuckles.

“I know that, baby, but I want to. I promise I’m okay with it. It’s gonna bring me peace to know you’re being taken care of.”

It wasn’t unusual for couples to get fill-ins. Those were usually assigned by a company, and they’d help one or both get off and get paid on top of it, almost like escorts.

That’s how, after filling in forms and doing some interviews, they found Youngjae.

The younger boy was lovely. A bright smile and beautiful eyes. They both got entranced by him. Jinyoung had took a liking on him, and trusted the beta to fulfill his alpha's needs while he was away.

He also thought it would be fun to hear about Youngjae’s reaction when his husband presented himself as submissive despite his rank.

Soon, they were both getting involved with the younger man.

Youngjae was fun to hang out with. He was funny, he was cute, he was hot. The couple would do it with him both separately and together. He seemed to enjoy their dynamic, and followed Jinyoung’s instructions so well the omega practically keened every time. Their dyamics were so natural. During sex and out of it. They had gotten used to his presence, and it was almost like Youngjae had always been there.

And with time, they both fell in love with him.

When the younger was dismissed by the company and they didn’t have an excuse to meet him anymore, both the alpha and the omega then realized how much they needed him. The hole Youngjae's absence had left didn't seem to get filled by anything else, and they wouldn't dare to  _think_ of getting a different fill-in.

So they reached out.

It was hard to. Neither the omega nor the alpha wanted to admit their feelings for the beta to each other at first, fearing their mate would take it the bad way, thinking they weren’t enough and that this wasn’t supposed to happen. Eventually, though, as the longing for the beta got too much to bear, they talked about it, and agreed on trying it out.

When they knocked on his door, Youngjae had cried when he saw them. He couldn’t believe the men were standing on his doorway telling him they wanted him. He’d thrown himself in Jinyoung’s arms and let Jaebum nuzzle his neck from behind, feeling like he’d finally found his place. He told them how he'd felt stupid for catching feelings for a mated couple who were paying him for his company, and how he cried at night sometimes when he figured they had probably gotten a new fill-in.

Only three months in, when they couldn’t take not being on the same level in their relationship, the omega and the alpha both mated him, and soon they were living together.

It wasn’t expected. None of them had ever imagined this would’ve happened to them. But once Youngjae was theirs, finally, they felt like there wasn’t another way their life was meant to go but this one. Their heats were already in sync, and their bodies already saw the three of them as one.

“Baby, you’re not being reasonable.” Jinyoung whispers into Jaebum’s mouth, gripping his hair in one hand, looking down at him from where he sits on his lap, the alpha’s cock buried inside his wet heat. “Are you going to behave?”

The older groans and nods, submissive as always. Jinyoung smiles at the way their scents get stronger and Youngjae moans next to them.

“Hyungie.” He calls out.

“Look at him, Jaebumie. Look at our baby beta. Don’t you wanna fuck him, love? He needs you.” The omega whispers with a sultry voice, rolling his hips slowly and teasingly.

“Yes. I do.” He says, doing his best to look at Youngjae without moving his head, hair still gripped by the omega’s fist. When the youngest’s eyes meets the alpha's, he whines, trashing around.

Since he was a beta who had been mated by both an omega and an alpha, his body reacted to the both of them. His cock would grow a knot when he was close to an orgasm and he’d also produce slick, which was dripping out of him in a constant stream.

Jinyoung reaches out and takes the younger’s cock in his hand, stroking it slowly but firmly, making him moan out.

“Oh love. You’re so hard, aren’t you? Do you want our alpha inside you?” He asks, a fond look in his eyes, like he always has for their beta.

“Y-yes, please.” Youngjae pants out.

Jinyoung lets go of his member and of Jaebum’s hair, getting off of him and letting the alpha slip out of him. “Take care of him.” He instructs. Youngjae opens his arms towards the older in an invitation, desperate for someone touching him, and Jaebum is quick to go over to him, slipping inside the beta’s heat already and thrusting desperately, kissing the younger’s plump lips.

Jinyoung feels his heart burst. To watch his lovers caring for each other in such a way, needing each other like he needs them too. It's so hot. Watching Youngjae squirm and open his legs wider as Jaebum thrusts desperately into his heat, almost growling against his lips.

Jinyoung moves to kneel behind Jaebum, and lays on top of him, sandwiching the alpha between himself and the omega, probably making the wolf inside him humiliated, which he knows Jaebum loves. He kisses Youngjae over the older's shoulder and grabs Jaebum's cheeks in his hands, squeezing. The alpha is still doing his best to pound into the beta, and Jinyoung notices Jaebum's cheeks are wet from the omega's slick, from when he was riding him, so he moves a teasing wet finger to the older's entrance and rubs his finger against it, making him moan out.

"Look at him, Youngjae, baby. Look at our alpha getting more desperate by a finger on his hole. What would your alpha friends think if they saw you like this, hm, Jaebumie?" He whispers into the older's ear as he pushes his middle finger in, biting his bottom lip at the way both the beta and alpha moan.

"Omega." The oldest moans, but doesn't manage to say anything else when Jinyoung starts moving his finger inside fast.

Jaebum uses his alpha strenght to lift both himself and the omega, and thrusts into Youngjae, who at this point is a moaning mess, and onto Jinyoung's finger. The omega moves to the side to admire the sight of his beta in pure bliss, legs wide open and hands clutching the sheets, cock wet hard against his belly. Jinyoung groans at the sight of it. He  _wants_ it.

“Wait, baby. Stop.” He tells Jaebum, who does as he’s told even though Youngjae whines. He pulls his finger out of the alpha.

“Oh baby, don’t you wanna fuck me?” He asks the beta, running his fingers through his hair and pecking his lips. The youngest seeks for his lips when Jinyoung pulls away from the kiss.

“Yes I do, hyung.” He tells him. “I want both my hyungs, please?”

Their alpha groans, still on top of Youngjae.

“Of course, love. You’re getting the both of us.”

Jaebum gets off of the youngest without needing to be told to, already knowing what he’s supposed to do.

Jinyoung lies on the bed and spreads his legs, motioning for Youngjae to get on him. The alpha helps the beta, who lies on top of the omega with a sigh, nuzzling his neck where Jaebum’s marked him, his own mark on the other side of Jinyoung’s neck.

The omega chuckles at their cute youngest and reaches in between them to hold his swollen member in his hand. He jerks him, smirking at Jaebum when Youngjae whines and thrusts into his fist. Then he stops, and makes soothing sounds at the crying beta as he presses the tip to his slick entrance. Youngjae understands his silent request and pushes in, whimpering as he does. The younger does his best, though, not to move.

“You can go now, baby.” Jinyoung tells Jaebum, who had been hungrily watching as they settled. The omega moves his hands down Youngjae’s back and grips his cheeks, pulling them apart so that the alpha can see his leaking hole.

The both of them moan, Jinyoung’s sweet omega scent in contrast to his dominant personality taking a toll on them like it always does.

“Go on.” He tells the alpha, who is quick to hover the both of them and push inside the beta once again, groaning. He pulls both of Jinyoung’s legs up and wrap them around Youngjae’s waist and pants.

“Can I?” He questions, to which the omega nods.

“You too, love.” Jinyounge tells the beta, who is moaning with his face buried in the crook of his neck. “I wanna see my babies making themselves feel good. Just for me.”

Youngjae is the one who moves first. Eager and desperate for release already. Jaebum is quick to follow, the two of them setting a pace and punching moans out of Jinyoung and each other with every thrust.

“ _Fuck_ baby.” The omega moans at a particularly hard one. “Keep it like that. Fuck our baby well.”

Youngjae whimpers, loving the dominance, being talked down to by his omega.

He’d wondered before how it had taken him so long to notice Jinyoung was the dominant vein in the olders' relationship, before he even was a part of it.

The alpha acted tough, and tried to maintain a reputation, but the beta felt like it might have been obvious to anyone but him how he was always seeking for his omega’s approval. Back then Youngjae had thought that was just something that happened when a couple was mated, and hoped one day he’d be doing that to someone he loved.

Now he had two mates he loved more than he thought possible, so his wishes were more than granted.

Jaebum pounded into him harshly as he pushed back onto him and then into Jinyoung. He was nearing his climax when the omega told them to stop once again.

Both the alpha and the beta whined in complaint, but none of them could deny anything to their omega in heat.

For some reason, Jinyoung’s heats just make him more dominant.

“Get off.” He told them, and they do as asked of, moving away and slipping out, almost crying from having been denied an orgasm. The omega pulls Youngjae to sit as he straddles him and tells Jaebum to get the beta’s hips on his lap.

Once they maneuver and are in position, the alpha pushes inside Youngjae, cursing, and the omega sits on him slowly.

“Ah, fuck. Making me feel so good, baby.” Jinyoung moans out, riding the beta quickly, drunk in his own heat. "Your cock feels so good in me. My baby beta. Our baby."

Youngjae lies there, moaning uncontrollably as he’s pounded and ridden, both of his mates making him feel so good. Jaebum wraps his arms around the omega’s waist and starts sucking on his neck, making him submit and have his head fall to the side to expose more of his neck. He takes Youngjae’s hands in his and intertwines their fingers, moaning out loud at how the beta clenches around him.

The beta is the first to come, knot growing and locking him in place inside Jinyoung as he shoots his load inside him, moaning and thrashing around, hips kicking. Jaebum is quick to follow, moaning out how good his mates are and how much they love him and locking inside Youngjae with his own knot.

The omega is whimpering and moaning loudly, one hand on the beta’s chest and the other gripping Jaebum’s hair for behind. The alpha reaches around and strokes the omega’s leaking cock as he tries to keep riding Youngjae even though the beta’s knot had grown inside him. The movements are quick and barely there, but the knot pressing against his prostate is merciless.

He comes, finally, around the youngest’s cock, crying out and shooting his come on Youngjae’s belly and Jaebum’s hand as both the beta and the alpha are still spurting out their come inside the other.

“Oh, baby. You were so good.” Jinyoung praises like he always does once they’ve all reached their climax. That’s not it for the day, but for now it’s enough for all of them. “And you, love, fucking me so good. The both of you did so well.” He breathes out.

Then he collapses. The alpha keeps him from crushing Youngjae, holding Jinyoung by the waist, and the beta helps him rest the omega over him, wrapping his arms around his hyung’s torso and smiling at Jaebum, who smiles back and runs his fingers through his sweat slick hair sweetly.

“So...” The oldest starts. “What are we gonna do now?” He asks.

And Youngjae has to chuckle, because in this position, all of them locked in place by their knots, they’re gonna have to wait for at least fifteen minutes until they shrink back.

**Author's Note:**

> SO WHAT DID YOU THINK?  
> Also goodnight  
> Please give me feedback, I love it <3  
> My twt is DoctorFatCat in case you guys wanna interact.  
> Bye.


End file.
